Several types of diode phase shifters have been devised such as switched line, hybrid coupled, loaded line and three element ".pi." or "T" circuits. The switched line circuit includes a pair of single-pole, double-throw switches for switching one of two lengths of transmission line into a circuit. In general, this circuit requires four diodes. Phase shift is obtained by switching between one line used as a reference path and a second line which provides a delay path. The hybrid coupled circuit includes a 3-decible hybrid with a pair of balanced diode switches connected to identical split arms of the hybrid. The hybrid coupled bit is used extensively because it achieves larger phase shifts while still using only two diodes. The loaded line circuit includes a number of pairs of switched susceptances spaced at one-quarter wavelength intervals along a transmission line. Phase shift is obtained as the susceptances are changed from an inductive to a capacitive state. Phase shift for this circuit is limited to about 45.degree. for a pair of diodes. Lastly, the .pi.-circuit consists of two shunt elements and one series element. Phase shift is obtained by changing the circuit elements between a low-pass and a high-pass condition. Phase shifts of the order of 90.degree. can be obtained with this circuit. Three diodes are required for the ".pi." circuit and the "T" circuit which is a dual of the ".pi." circuit.